Switching system for electrical organs



March 15, 1966 w. MUNCH, JR

SWITCHING SYSTEM FOR ELECTRICAL ORGANS 4 Sheets-Sheet 1 Filed Oct. 29,1962 ATTORNEYS R O T. N E V m A TER MUNCH 4R. BYJ

ol o March 15, 1966 w. MUNCH, JR

SWITCHING SYSTEM FOR ELECTRICAL ORGANS Filed Oct. 29, 1962 4Sheets-Sheet 2 INVENTOR. WALTER MUNCH Jrz.,

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5 um 4 7mm ATTORNEYS.

March 15, 1966 Filed Oct. 29, 1962 W. MUNCH, JR

SWITCHING SYSTEM FOR ELECTRICAL ORGANS lllllllllll 4 Sheets-Sheet 5Fig.7

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March 15, 1966 w. MUNCH, JR 3,240,857

SWITCHING SYSTEM FOR ELECTRICAL ORGANS Filed Oct. 29, 1962 4Sheets-Sheet 4 INVENTOR. WALTER MUNCH JR,,

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United States Patent Ohio Filed Oct. 29, 1962, Ser. No. 233,560 7Claims. (Cl. 841.01)

The invention relates to improvements in tone signal switching systemsfor electrical organs. In particular, it has to do with types ofinstruments in which generators are provided for tone signals in acertain register consisting of one or more octaves, but in which tonesignals in a still lower octave or octaves are derived from some atleast of the same oscillation generators in a circuit having one or morefrequency dividers incorporated therein. In such instruments a saving incost is attained with the sacrifice of polyphonism in the octave oroctaves below the first mentioned range.

The invention is useful not only in providing low tone signals uponactuation of the keys in a pedal clavier, but also may be used toprovide tone signals for the lowermost octave or octaves when actuatedby the keys of a manual keyboard.

For example, it has been a practice in some electrical musicalinstruments to provide a frequency divider, such as a flip-flopelectronic circuit to halve the frequency of tone signals, so as toattain a 16 pedal note which is not available as such from the generatorsystem of the organ. Many electrical organs make use of twelve series ofelectronic oscillators, where the controlled oscillators in each serieshear an octave relationship to each other, the series being related toeach other as the twelve semitones of the tempered musical scale, as inthe United States Patent No. 2,233,948 to Koch. Where in a lower octaveor octaves polyphonism is not necessary, it has been found that thecombination of one or more flip-flops and a simple switching system ismore economical than providing one or more additional electronic dividerstages in each of the series. The invention will be described inconnection with such an instrument, although the specific nature of thesources of oscillations does not constitute a limitation upon theinvention.

It has also been a practice to provide a group of, say, thirteen pedaloperated, single pole, double throw switches in connection with theflip-fiop divider. In the oil position these switches are in series, theseries being connected at one end to the flip-flop. When a pedal key isactuated, the series chain is broken, and the switch of the pedal keyconnects the flip-flop to a signal source in the generator system of theinstrument thereby directing its tone signal to the flip-flop fordivision to produce a lower pitch. Economies are attained in this way;but experience has shown that poor contact in any one switch of theseries chain can cause some or all of the pedal notes to fail to reachthe output system. Also, two fixed and one movable contact are requiredfor each note, with the attendant necessity for individual adjustment.

It is a further object to provide an improved switching construction ofthe class described, which is easier to assemble and adjust.

It is a still further object of the invention to provide a switchingsystem of the class described, which is adaptable either for pedalkeying or for manual keying purposes.

These and further objects, which will be obvious to one skilled in theart upon reading these specifications, are accomplished by thoseembodiments to be described and which are illustrated in theaccompanying drawings.

FIG. 1 is a schematic diagram of a prior art system.

FIG. 2 illustrates an embodiment which is applicable to a pedal keyingsystem.

FIG. 2a is a cross sectional view on an enlarged scale along the sectionline 2a2a of FIG. 2.

FIG. 3 shows an embodiment incorporated into a manual keying system.

FIG. 4 is a plan view of a pedal structure employing the switchingsystem of the present invention.

FIG. 5 is a partial plan view of the elements of FIG. 4 on an enlargedscale.

FIG. 6 is a cross sectional view of a portion of FIG. 5.

FIG. 7 is a partial side elevation of a pedal structure employinganother embodiment of the switching system of the present invention.

FIG. 7a is a plan view of the pedal down stop and wire switch elementengaging means of the structure of FIG. 7.

FIG. 8 is a partial plan view of a commercial embodiment of the switchof FIG. 3.

Reference is now made to FIG. 1 wherein the essential elements of aprior art structure are represented as a series of continuouslyoperating tone signal sources 1, 2, 3, 4, etc., which are connectable bysingle-pole, double throw switches 5, 6, 7, 8, etc., to a seriescombination of a flip-flop 9, a tone color filter 10, a stop switch anda sound output system 12. One skilled in the art will be aware that asource 1, for example, may generate a complex wave of say 128 c.p.s.,which, upon actuation (by a pedal key not shown) of the movable contactof switch 5 to its upper position, will be transmitted to the flip-flop9. The output of this dividing circuit may be, for example, 64 c.p.s.,which, in turn, may be modified as desired by a suitable tone colorfilter 10. Upon actuation of a stop tab (not shown) the stop switch 11makes the desired tone available to the output system 12, which may bethought of as comprising a suitable electronic amplification system andone or more loud speakers.

In the practice of the invention, a gang switch is provided including aplurality of movable switch .elements. These switch elements may be inthe form of resilient wire or wire-like members. Each such .element isconnected at one end to a generator in the rank of generators to whichreference has been made above. The movable switch members extend ingeneral parallelism, and are connected at their other ends to playingkey means so as to be moved upwardly or downwardly by them. Across allof the movable switch members in the group, there extends a transversemovable member which is connected through one or more flip-flop dividersand tone color means to an output system. The actuation of any given keyin the group first brings the movable contact member appropriate to thatkey against the transverse movable member, thus coupling the appropriategenerator to the flip-flop divider. At the same time, it moves thetransverse movable member further away from the wirelike elements of theother keys in the group. In one aspect of the invention, this makes itunlikely that the wire-like element of any other playing key willcontact the transverse movable element. In another aspect of theinvention means are provided which render such accidental contactimpossible. Each switch, however, operates independently, and thetransmission of oscillations from a generator to the flip-flop divideris not dependent upon the operation of any other switch.

To present one embodiment of this invention, FIG. 2 illustratesdiagrammatically a switching system for a group of say thirteen pedalkeys in an abbreviated pedal clavier for a small electronic home organ.Five pedal keys are indicated at 13, 14, 15, 16 and 17. These will beunderstood as pivoted at 18, 19, 20, 21 and 22 to a base member 23 ofsome suitable character. No attempt has been made to illustrate theblack keys of the clavier.

The base is shown as supporting an insulative panel 24 on edge. Certainmovable wire-like switch contact members 25, 26, 27, '28 and 29 areshown as supported at one end on the panel 24 and also as connected atthat same end to generators 30, 31, 32, 33 and 34 respectively. Thewire-like contact members (which may be of highly conductive spring wireplated with silver or other metal suitable for electrical contactpurposes) may be mounted on the panel 24 by passing their ends throughand soldering them to grommets fastened in the panel. The elements 25 to29 inclusive may be looped intermediate their ends as shown to increasethe range of their resilient action. The outer ends of the wire elements25 to 29 will be engaged as shown in upstanding elements 35, 36, 37, 38and 39 on the inner ends of the pedal keys. These parts may beinsulative in character, or if not, they will be provided withinsulative grommets as well understood in the art. It will also be seenfrom the diagrammatic figure that when the keys are in the restposition, the wire elements 25 to 29 inclusive lie within a singleplane.

A U-bar 40 is shown with its base lying above the plane of the wireelements 25 to 29. The legs of the U- bar are pivoted at 41 and 42 toupstanding insulative brackets 43 and 44 mounted on the base 23. Thedownward position of the base of the U-bar is defined and maintained byinsulative abutments 45 and 46; and the U-bar is biased to the downwardposition by springs 47 and 48 or any other suitable means.

As shown in section in FIG. 2a, the U-bar 40 will have a sutficientdepth for rigidity and preferably is provided with a plated contact wire49 along the lower edge at least of its base. Electrical contact may bemaintained with the U-bar by one or more wire elements 50 which areengaged with the U bar or with its wire edging 49, but are not engagedwith any key.

The contact wire 50 is connected with a lead 51. This lead is shown asconnected directly with tone color filters 52 and 53 having stop switchmeans 54 and 55 leading to an output bus 56. The output bus is shown asconnected to an output system 57. By the means just described 8' tonesin various tone colors may be derived in the output system.

The lead 51 from the U-bar is also shown as connected through aflip-flop divider 58 to a bus 59. Between this bus and the output bus 56are shown a plurality of filters 60 and 61 each with its stop switch 62or 63. By reason of the divider 58 in the circuit, if the oscillationspassing through the tone color filters 52 and 53 may be classed as 8tones, the oscillations passing through the filters 60 or 61 may beclassed as 16' tones. In the usual organ the filters 52 and 53 will beof such character as to give flute and horn timbres, while the filters60 and 61 will be of such character as to give diapason and bourdonvoices. If deeper tones are desired, the header 59 may be connectedthrough a second flip-flop divider 64 and a tone color filter 65 andstop switch 66 to the output header 56. In this way 32 tones may bederived in the output system.

FIG. 2 is diagrammatic in nature but will serve to illustrate theoperation of the mechanism. The base of the U-bar 40 is normallymaintained out of contact with any of the movable wire-like switchelements. Upon the depression of any one of the pedal keys, such as thekey 13, its wire contact element 25 will be moved upwardly into contactwith the wire 49 on the edge of the U-bar. A tone signal will then betransmitted to the output system in a way which will be clear from thedescription above. But the upward movement of the wire contact element25 will result in the upward movement of the base of the U-bar (whichswings about its pivots 41 and 42) so that the base of the U-bar will bemoved further away from the wire contact elements 26 to 29, making anyaccidental contact of these elements with the U-bar very unlikely.

In electrical organs having an abbreviated pedal clavier, it is thepractice to play upon such a clavier monophonically, i.e., the organistintentionally strikes only one pedal key at a time. The use of the U-barconstruction hereinabove described eliminates the chance that a slightinadvertent depression of a pedal key, when one pedal key has been fullydepressed, will connect a second generator to the output system. It istrue that an equal and concurrent full depression of two separate pedalkeys could result in the simultaneous derivation of two signals from twodifferent sources in the lead 51; but the chances of this occurringinadvertently are extremely small, so that the arrangement is entirelysatisfactory for an instrument with an abbreviated pedal clavier.

Turning now to FIG. 3, there is diagrammatically shown a switchingarrangement which, while primarily designed for use with manualkeyboards in electrical musical instruments is nevertheless adaptablefor use with the more extended types of pedal claviers. A switchingarrangement extending over more than one octave is shown. On aninsulative base 67 there are fastened a series of wire-like movableswitch contact devices 68 to 79 inclusive for tones which will be anoctave below the lowest octave of generators in a generator rank of theinstrument. The right hand end of the switch assembly is shown asbroken; but it may be understood that movable contact elements 80 and 81are representative respectively of the lowest generator in the generatorrank and of a generator twelve semitones thereabove. The contactelements 68 to 79 are diagrammatically indicated as connectedrespectively with generators 82 to 93 inclusive. Contact element 80 willalso be connected to generator 82 While contact element 81 will beconnected to generator 93. These connections will be effected throughsuitable isolative resistors (not shown) as is current practice in theart.

Normally, in instruments employing a rank of continuously operatinggenerators, resistive or gradual contact switch means are employed forthe derivation of oscillations in accordance with the requirements of amusical composition. The use of such gradual contact switches avoids keythump and key click. Any type of resistive switch may be employed suchas the structures shown in United States Patent No. 2,215,124 in thenames of Koch and Jordan, dated September 17, 1940. In FIG. 3 the righthand portion of the switching assembly is of a type set forth andclaimed in a copending application in the name of Marion B. Gregoryentitled, Variable Resistance Key Switch, filed October 29, 1962, SerialNo. 233,529. Thus the base or panel 67 is shown as carrying aninsulative fulcrum bar 94 to control the action of the wire-like movablecontacts, and the stationary contact means is a bus or wire 95 coveredwith a resistive coating or body 96 which is preferably deformable. Thebus 95 is indicated as connected to a lead 97, connected to voicingmeans, one of which is shown as a filter 98 and stop switches one ofwhich is shown at 99 and to an output system 100. By these means, andthe use of other similar switches connected to other generators in thegenerator rank, tones of different timbre can be developed in the outputsystem. Furthermore, the skilled worker in the art will understand thatthe instrument may comprise a plurality of banks of switchessimultaneously operable by the playing keys, especially where thederivation of octavely related oscillations in different headers isdesired for voicing purposes. In FIG. 3 a purely diagrammaticillustration of a connection 101 between the movable contact member 68and a playing key 102 is shown, it being understood that the severalmovable switch elements will be connected respectively with playing keysin a manual or clavier.

The movable contact elements 68 to 79 are arranged to provide an extranumber of notes of frequencies an octave below the frequencies of thelowest generators in the generator rank of the instrument. Upon thedepression of any of the contact elements 68 to 79 by its appropriateplaying key contact will be made with a wire element 103 which is shownas extending transversely beneath the movable contact elements. Thisdoes not provide for resistive or gradual contact switching in thelowermost octave; but initial transients are of less importance in lowfrequency registers.

The wire element 103, which is fastened to the panel 67 at one end, asat 104 not only extends beneath the movable contact elements 68 to 79but lies somewhat aslant to the plane of these contact elements. Thefree end of the wire, which may be provided with an insulative andanti-friction bushing 105 will usually lie within a bracket element 106fastened to the panel 67 and serving to guide the motion of the wire.Upon the depression of any one of the movable contact elements by meansof its appropriate key, it will be brought into contact with the Wire103. This wire is connected, through a flip-flop divider 107 to a lead108 which connects with the lead 97. An additional tone color circuit109 and its stop switch 110 is also shown. The more elaborate circuitrywhich has been diagrammatically illustra-ted in FIG. 2 can be used inconnection with the switch means of FIG. 3, and by the same token, theskilled worker in the art will understand that more than one octave ofnotes lower than the lowest full octave of generators in the generatorrank may be provided monophonically through the use of two or more flipflop dividers in series.

The operation of movable contacts 68 to- 79 will be similar to thatdescribed in connection with FIG. 2. The wire member 103 acts in a waysimilar to the base of the pivoted U-bar, in that if a movable contactmember is brought against it through the actuation of a playing key, thewire 103 will be moved away from the plane of the unactuated contactmembers. But because the wire 103 lies aslant to the plane of theunactuated contact members, its depression by an actuated contact memberwill result in the movement of that part of the wire extending beyondthe movable contact member in one direction so far away from the othermovable contact members lying beyond the actuated member in the samedirection, that these movable contact members cannot possibly be broughtagainst it even though their respective keys be fully depressed. Thus,monophonism will be enforced; and only the highest note or lowest notein the octave can sound, depending upon which end of the wire 103 ispivoted to the insulative panel 67.

FIGS. 4, 5 and 6 illustrate a commercial embodiment of a pedal clavierarrangement, in which like parts have been given like index numerals andwill not be redescribed. The arrangement includes a frame comprising thebase member 23, the end members 43 and 44 and a pair of spacedlongitudinal angle irons 111 and 112. The pedal keys, one of which isindicated at 113 in FIG. 6 are in effect pivoted to the angle ironmember 111 and the base 23 by a bolt, collar and resilient washerstructure shown at 114 in FIG. 6. An adjustable bolt arrangement 115 inthe same figure is used to level the pedal keys in their unactuatedpositions and to limit the extent of their movement when actuated. Thisarrangement engages angle iron means 112. The keys may be urged towardtheir unactuated positions by coil springs 116 engaged between the rearends of the keys and the base 23. The insulative panel 24 is so markedand it is shown as held to the base 23 by bracket means 117. Thearrangement of the movable switch con-tact means and the U-bar will bethe same as that hitherto described. The contact element 50 whichengages the U-bar at all times may, if sufficiently strong andresilient, take the place of spring means 47 and 48 diagrammaticallyillustrated in FIG. 2.

A somewhat different arrangement for the pedal clavier is shown in FIGS.7 and 7a. Here a base 117 is provided, and the pedal keys, one of whichis shown at 118, are pivo-tally mounted to the underside of the base byleaf spring means 119. The pedal keys carry plungers 120 which extendupwardly through bushings 121 in holes 122 in the base. The plungerscarry heads 123 Which serve a dual purpose. They limit the extent of thedownward movement of the pedal keys upon actuation. Also, they areprovided with extensions 123a which engage and operate the contact wires124. These are supported on the vertical insulative panel 125 similar tothe panel previously described.

A return spring 126 for the pedal keys may be engaged between the head123 and the bushing 121 as shown, with the interposition of a feltwasher 127 for sound deadening purposes.

In this instance the U-bar 128 will be pivoted to brackets 129 on thebase, and will lie beneath the movable wire contact elements as shown.It may be urged toward the contact elements by hinge spring means 130.Needless to say, stops (not shown) will be provided to define the upperposition of the U-bar. The contact wire hitherto described in connectionwith the U-bar will now lie along its upper edge as at 131. Theoperation of the structure of FIGS. 7 and 7a will be clear from thedescription above.

FIG. 8 shows a commercial embodiment or part thereof corresponding tothe switching means diagrammatically illustrated in FIG. 3. Like partshave been given like index numerals. It will be understood that theinsulative panel 67 may be extended in either direction. The panel isshown as provided at its rear edge with soldering lugs collectivelyindicated at 132. Grom- Inets 133 are fastened to the insulative panel,and downturned ends of the movable contact members are soldered to thesegrommets. The isolating resistors which have heretofore been mentionedmay be soldered between the grommets and the lugs 132 as indicated at134.

Modifications may be made in the invention without departing from thespirit of it. The invention having been described in certain exemplaryembodiments, what is claimed as new and desired to be secured by LettersPatent is:

1. In a switching system for an electronic organ having a plurality ofsources of musical tone signals and an output system, the combinationcomprising:

(a) a plurality of movable switch contacts respectively coupled to saidsources,

(b) a movable common contact member coupled to said output system andbiased toward said switch contacts but normally out of contacttherewith, and

(o) a plurality of keying means respectively associated with said switchcont-acts for urging them selectively against said common contact memberand for moving the latter away from unselected switch contacts.

2. The combination claimed in claim 1 wherein said common contact membermay be displaced substantially equally from all said contacts, wherebytwo of said contacts will not touch said common contact member unlessthe keying means associated therewith are depressed a substantiallyequal distance.

3. The combination claimed in claim 1 wherein said common contact memberis movable about a point substantially in line with said contacts,whereby when said common contact is moved by a movable switch contact,it will be carried to a position so far away from certain other movableswitch contacts in the group that said other movable switch contactscannot establish connection with said common contact even when fullyactuated.

4. The combination claimed in claim 3, said output system including:

(a) a frequency divider connected to said common contact member and 7(b) a tone color and amplification system connected to said frequencydivider. 5. The combination claimed in claim 4 including: (a) at leastone additional key switch connected directly to said tone color andamplification system. 6. In a structure of the class described, aninsulative panel means, a plurality of wire-like movable contactelements extending in substantial parallelism and mounted at one end onsaid panel, a plurality of playing keys, operative connections betweensaid playing keys and respective ones of said movable contact elements,a common cont-act member having a portion at least extendingtransversely of said movable contact elements and normally lying in aposition to be contacted by said movable contact elements upon actuationthereof by their respective playing keys, said common contact memberbeing mounted so as to be movable by said movable contact elements to aposition further away from other movable contact elements in the group.

7. The structure claimed in claim 6 wherein the said common contactmember is in the form of a pivoted U-bar biased towards said movablecontact elements but held out of contact with un-actuated ones of saidmovable contact elements by abutment means.

References Cited by the Examiner UNITED STATES PATENTS 2,846,916 8/1958Osborne et al. 2,931,877 5/1960 Henley. 2,969,439 1/1961 Dubois 200-18ARTHUR GAUSS, Primary Examiner.

1. IN A SWITCHING SYSTEM FOR AN ELECTRONIC ORGAN HAVING A PLURALITY OFSOURCES OF MUSICAL TONE SIGNALS AND AN OUTPUT SYSTEM, THE COMBINATIONCOMPRISING: (A) A PLURALITY OF MOVABLE SWITCH CONTACTS RESPECTIVELYCOUPLED TO SAID SOURCES, (B) A MOVABLE COMMON CONTACT MEMBER COUPLED TOSAID OUTPUT SYSTEM AND BIASED TOWARD SAID SWITCH CONTACTS BUT NORMALLYOUT OF CONTACT THEREWITH, AND (C) A PLURALITY OF KEYING MEANSRESPECTIVELY ASSOCIATED WITH SAID SWITCH CONTACTS FOR URGING THEMSELECTIVELY AGIANST SAID COMMON CONTACT MEMBER AND FOR